This is a double-blind, randomized, controlled trial of enteral glutamine supplementation in patients with AIDS, wasting, and fat malabsorption. Subjects will be randomized to receive one of two tube-feeding formulas. The study product will be supplemented with glutamine; the control product will be isocaloric and isonitrogenous. The effect of glutamine on small intestinal architecture and function, whole body and skeletal muscle protein synthesis, strength and quality of life will be assessed.